(1) Field of the Invention
The invention relates to a multipoint conference among plural participants, and more particularly to a pointing-control system used for collaborating such a multipoint conference.
(2) Description of the Prior Art
Thanks to the improvement in computer and networking technology that the multipoint conference becomes one of the most popular conferencing means for the participants communicating opinions and messages each other.
Referring to FIG. 1A and FIG. 1B, a framework of a multipoint conference and a block diagram of a pointing-control system for the multipoint conference are shown, respectively. The multipoint conference includes a plurality of computers 1 (participants), a gateway 2, a display 3 and a conference-control module 4. Each of the computers has a conference-control module 4 and a pointing apparatus 6.
Every of the computers 1 has networking capability, either wired or wireless, and can establish network connection to gateway 2. The display 3 can be a liquid crystal display, a plasma display TV, or a digital projector, any of which has a DVI or a VGA interface. In the figures, a typical digital projector having a screen is used as an example. When the digital projector establishes a connection with the gateway 2, the projector can project a presentation frame transmitted from the gateway 2 onto the screen. Generally, the multipoint conference can only be taken place through the conference-control module 4.
The conference-control module 4 is an application program to make the multipoint conference possible. In the art, the gateway 2 for multipoint conferences usually includes a built-in conference-control module 4, and thereby the computer 1 to join the multipoint conference can download the conference-control module 4 through the gateway 2. Then, the conference-control module 4 can be executed in the computer 1 so as to have the user of the computer 1 join the multipoint conference.
When a multipoint conference begins, the conference-control module 4 would define the participant (computer) having the highest priority number to be the host computer 1a. The host computer 1a has the right to assign any of the computers 1 to be the report computer 1b. The conference-control module 4 would transmit the presentation frame 5 of the report computer 1b to the gateway 2 and further to show the presentation frame 5 on the display 3. At this current time, the report computer 1b takes the mission to report his/her presentation frame 5 to all the other participants (computers 1) of the multipoint conference.
It is easy to see that the aforesaid multipoint conference has the advantage in that a computer 1 can be the report computer 1b anytime only through the recognition of the host computer 1a. Then, he/she can demonstrate his/her materials on the display 3 through the gateway 2.
However, in the aforesaid multipoint conference, the display 3 can only display the presentation frame 5 transmitted from the report computer 1b and a symbol of the pointing apparatus 6b (a mouse cursor for example) of the report computer 1b. Any discussion from the other participants can only be noticed through oral expressions or a laser point projected on the display 3. Obviously, the oral expressions are hardly to be quickly related to a specific point in the presentation frame 5. Also, the laser point generated by a laser pointer prepared by individual participant is usually monochromatic (red for example). Thus, in a discussion situation involving more than two participants, plural laser points on the display 3 would be quite possible to make the discussion chaotic.